Conventional medical laboratory systems use a variety of processes when analyzing medical specimens. Some processes involve identifying medical specimens contained in sample tubes so that laboratory systems know how to process them. In some instances, the heights of component layers in a liquid need to be accurately determined so that an aliquotter can aspirate and dispense the correct amount of the liquid component.
In some instances, however, the ability to detect the level of a liquid may not be accurate. This can cause problems if too little or too much liquid or liquid component is aspirated by the aliquotter. Further, faulty information regarding the available serum volume in a sample tube may cause the analyzer probes to get stuck in e.g., gel or cruor, causing instrument downtime. This may result in monetary losses and may delay analysis results.
Embodiments of the invention address these and other problems, individually and collectively.